16.3 NIMS/ICS & Hazardous Materials Response

NIMS and ICS Foundations

The National Incident Management System (NIMS) provides a consistent nationwide framework for incident management. Within NIMS, the Incident Command System (ICS) is the standard on-scene command structure. MPOETC references IS-100.C (Introduction to the Incident Command System) as the baseline ICS course. Pennsylvania officers are expected to understand ICS for multi-agency and emergency operations.

Core ICS Features

Command and General Staff

Command Staff (report directly to the Incident Commander):

• Incident Commander (IC) — overall authority
• Public Information Officer (PIO) — media/information
• Safety Officer — responder safety
• Liaison Officer — interagency coordination

General Staff (Section Chiefs):

Unified Command vs. Single Incident Commander (Exam Trap)

A single Incident Commander manages most incidents. Unified Command is used when an incident involves multiple agencies, multiple jurisdictions, or multiple disciplines that each have statutory authority and shared responsibility. In Unified Command, representatives from each agency share command and jointly develop a single Incident Action Plan.

Scenario — Multi-agency crash with hazmat: A tractor-trailer collision on a state highway releases an unknown chemical. The response involves municipal police, state police, fire, EMS, the hazmat team, and PennDOT. Because multiple agencies with different authority share responsibility, Unified Command is the appropriate structure — not a single IC from one agency.

NIMS Components

NIMS is built on five components:

1. Preparedness
2. Communications & Information Management
3. Resource Management
4. Command & Management
5. Ongoing Maintenance

Hazardous Materials Response

DOT Placarding — Transport Vehicles

The U.S. DOT requires color-coded diamond placards on vehicles transporting hazardous materials. There are 9 hazard classes:

NFPA 704 Diamond — Stationary Facilities

The NFPA 704 diamond is the four-quadrant sign displayed on stationary facilities (factories, storage buildings) to alert responders. The quadrants are:

Numbers run 0–4, with 4 = severe hazard and 0 = minimal.

Exam trap: Do not confuse the DOT placard (vehicle, 9 classes) with the NFPA 704 diamond (facility, four colored quadrants). They are different systems.

Emergency Response Guidebook (ERG)

The Emergency Response Guidebook (ERG) is the first-responder reference for hazardous-materials incidents. Use the UN/ID number or the placard name to look up the guide page. Each guide page provides:

• Initial isolation distance — radius to isolate around the spill
• Protective action distance — downwind distance for evacuation
• PPE / fire-response guidance
• Evacuation recommendations

First-Responder Priorities

At a hazmat incident, the first-responder decision sequence is:

1. Scene size-up — observe placards, labels, container types, wind direction.
2. Deny entry / isolate — keep everyone out; establish perimeter.
3. Identify the product — use placard/UN number + ERG.
4. Call the hazmat team — do not attempt advanced mitigation.
5. Establish hot/warm/cold zones — contamination control.
6. Stage uphill and upwind — avoid vapor travel and runoff.
7. Protect drainage and waterways — prevent environmental spread.

Scenario: Officers arrive at a truck crash displaying a Class 3 (flammable liquid) placard with UN 1203 (gasoline). The officer isolates the area, looks up Guide 128 in the ERG for initial isolation and protective action distances, requests fire/hazmat, stages responders uphill and upwind, and keeps ignition sources away.

Exam Traps

• Trap: Assuming a single IC is always used. Wrong. Multi-agency/multi-jurisdiction incidents use Unified Command.
• Trap: Confusing NFPA 704 colors — e.g., placing health at the top. Correct: blue = health (left), red = flammability (top), yellow = reactivity (right), white = special (bottom).
• Trap: Approaching the scene downhill/downwind. Wrong. Always stage uphill and upwind.
• Trap: Confusing DOT placard classes with the NFPA diamond system. They are separate systems for different contexts.